Mascarenhas Desmond D, Herndon David N, Arany Istvan
Mayflower Organization for Research & Education, Sunnyvale, CA.
Transporin, Inc., Sunnyvale, CA.
Biologics. 2017 Jul 17;11:97-106. doi: 10.2147/BTT.S136188. eCollection 2017.
Nephrilin peptide, a designed inhibitor of Rictor complex (mTORC2), exerts pleiotropic protective effects in metabolic, xenobiotic and traumatic stress models. Stress can generate enduring epigenetic changes in gene function. In this work we examine the possibility that nephrilin treatment protects against acute and enduring global changes in oxidative metabolism, with a focus on the Rictor-complex-mediated activation of Rac1, a subunit of NADPH oxidase (Nox) via PKCs, Prex1 and p66shc.
Given the wide range of animal models in which nephrilin peptide has previously demonstrated effectiveness in vivo, we chose three different experimental systems for this investigation: dermal fibroblasts, renal proximal tubule epithelial cells (PTECs), and kidney tissue and urine from an animal model of burn trauma in which nephrilin was previously shown to prevent loss of kidney function.
(1) Nephrilin protects dermal fibroblasts from loss of viability and collagen synthesis after ultraviolet A (UV-A) or HO insult. (2) Nephrilin reduces reactive oxygen species (ROS) formation by HO-treated (PTECs) with or without nicotine pretreatment. Using RNA arrays and pathway analysis we demonstrate that nicotine and HO-treated PTECs specifically induced Rac1 gene networks in these cells. (3) Using kidney tissue and urine from the burn trauma model we demonstrate significant elevations of [a] 8-aminoprostane in urine; [b] kidney tissue histone modification and DNA methylation; and [c] post-transcriptional phosphorylation events consistent with Rac1 activation in kidney tissue.
Nephrilin protects against oxidative stress, possibly by modulating the activation of Rac1.
Nephrilin肽是一种设计的Rictor复合物（mTORC2）抑制剂，在代谢、外源性物质和创伤应激模型中发挥多效性保护作用。应激可在基因功能上产生持久的表观遗传变化。在本研究中，我们探讨了Nephrilin治疗预防氧化代谢急性和持久整体变化的可能性，重点关注Rictor复合物介导的通过蛋白激酶C（PKCs）、Prex1和p66shc激活NADPH氧化酶（Nox）的一个亚基Rac1。
鉴于Nephrilin肽先前已在多种动物模型中证明其体内有效性，我们选择了三种不同的实验系统进行本研究：皮肤成纤维细胞、肾近端小管上皮细胞（PTECs），以及来自烧伤创伤动物模型的肾组织和尿液，之前已证明Nephrilin可预防该模型中的肾功能丧失。
（1）Nephrilin保护皮肤成纤维细胞在受到紫外线A（UV-A）或羟基自由基（HO）损伤后活力和胶原蛋白合成不受损失。（2）无论有无尼古丁预处理，Nephrilin均可减少HO处理的PTECs中活性氧（ROS）的形成。使用RNA阵列和通路分析，我们证明尼古丁和HO处理的PTECs在这些细胞中特异性诱导Rac1基因网络。（3）使用烧伤创伤模型的肾组织和尿液，我们证明尿液中[a]8-氨基前列腺素显著升高；[b]肾组织组蛋白修饰和DNA甲基化；以及[c]与肾组织中Rac1激活一致的转录后磷酸化事件。
Nephrilin可能通过调节Rac1的激活来预防氧化应激。
